import boards


PARAM_NEXT = 'next'
PARAMETER_METHOD = 'method'


class DispatcherMixin:
    """
    This class contains a dispather method that can run a method specified by
    'method' request parameter.
    """

    def __init__(self):
        self.user = None

    def dispatch_method(self, *args, **kwargs):
        request = args[0]

        self.user = request.user

        method_name = None
        if PARAMETER_METHOD in request.GET:
            method_name = request.GET[PARAMETER_METHOD]
        elif PARAMETER_METHOD in request.POST:
            method_name = request.POST[PARAMETER_METHOD]

        if method_name:
            return getattr(self, method_name)(*args, **kwargs)


class FileUploadMixin:
    def get_max_upload_size(self):
        return boards.settings.get_int('Forms', 'MaxFileSize')


class PaginatedMixin:
    def set_page_urls(self, paginator, params):
        params['prev_page_link'] = paginator.get_prev_page_url()
        params['next_page_link'] = paginator.get_next_page_url()